Adsorption thermodynamics and kinetics of mancozeb onto poly-o-toluidine Th(IV) phosphate-a nano-composite cation-exchanger-and its application as a mancozeb-sensitive membrane electrode

Abstract

A newly-synthesized poly-o-toluidine Th(IV) phosphate nanocomposite cation-exchanger was employed as an adsorbent to study the adsorption thermodynamics and kinetics of Mancozeb from aqueous media. Some parameters such as the Freundlich constants, the thermodynamic equilibrium constant (K 0), the standard free energy change (δG), the standard enthalpy change (δH) and the standard entropy change (δS) were determined. Thermodynamic analysis revealed that the adsorption of Mancozeb onto poly-o-toluidine Th(IV) phosphate was exothermic, spontaneous and decreased as the temperature was increased from 25 °C to 45 °C. A pesticide-sensitive membrane electrode was fabricated using poly-o-toluidine Th(IV) phosphate as an electro-active composite material. Its sensitivity towards Mancozeb was monitored.